The In Vitro Research On The Color Stability Of Resin Infiltration And Filtek Z350 Nano Composite Resin To Initial Lesions In Enamel Caries

Objectives: In this vitro study,the color change of artificial caries lesions located in enamel was evaluated after resin infiltration(Icon, DMG,Hamburg Germany)or Filtek Z350 nanocomposite resin in red wine,coffee,cola,tea and artificial saliva.Methods: Enamel specimens(n=60)were exposed to demineralizing solution(4 week s)and treated with resin infiltration.Fifteen standard specimens of Filtek Z350 nanocomposite resin shade A2 were produced. The specimens were subdivided and immersed in: A(red wine), B(coffee), C(cola), D(tea)and E(artificial saliv a).The color values of the specimens were determined by a digital colorimeter on CIE1976-L*a*b* color stem before and after immersion at2, 4, 8 weeks,col or difference(△E) was calculated as:△E=[(ΔL*)2+(Δa*)2+(Δb*)2]1/2.The variatio n in color(ΔE) was analyzed by ANOVA(one-way) and Tukey’s tests.Results: 1.Red wine,coffee,cola and tea all caused visible color changes for both res ins(△E>3.7). The color differences increased with the increase of immersion ti me.Artificial saliva caused the clinical acceptable color change for Filtek Z350 group and icon group.(△E<3.7). 2.The color difference of different soaking solution and different time(1)Icon group : Immersed in 2 weeks,ΔE:red wine>coffee>cola>tea>artificial saliva,comparing di fferences between five groups was statistically significant(P<0.05). Immersed in 4 weeks,ΔE:red wine≈coffee≈cola>tea>artificial saliva,red wine,coff ee and cola group has no statistically significant difference(P>0.05), and the difference between the other groups was statistically significant(P<0.05). Immersed in 8 weeks,ΔE:red wine≈coffee>cola>tea>artificial saliva,red wine and coffee group has no statistically significant difference(P>0.05),and the differe nce between the other groups was statistically significant(P<0.05).(2)Filtek Z350 group:Immersed in 2 weeks,ΔE:red wine≈coffee >tea≈cola>artificial saliva,red wine an d coffee group has no statistically significant difference(P>0.05,)and the differ ence between the other groups was statistically significant(P<0.05). Immersed in 4 and 8 weeks,ΔE:red wine>coffee >tea>cola>artificial saliva,comp aring differences between five groups was statistically significant(P<0.05). 3.After immersed in red wine coffee and cola, Icon group showed more signifi cant color change than Filtek Z350 group(P<0.05); After immersion in tea an d artificial saliva, Icon group and Filtek Z350 group has no statistically signifi cant difference(P>0.05).Conclusions: 1.Both materials showed significant color change after immersion in extrinsic s taining solusions, The color differences increased with the increase of immersio n time. 2.Icon immersed in red wine,coffee and cola was less color stable than in tea.Filtek Z350 immersed in red wine,coffee and tea was less color stable than in cola. Immersed in red wine,coffee,cola and tea,ΔE beyond the scope of clinic al acceptable and caused visible color changes 3.Icon was less color stable than Filtek Z350 in red wine, coffee or tea.